1. Field of the Invention
The present invention relates to a multicylinder internal combustion engine in which a uniform fuel-air mixture is supplied to the respective cylinders from a carburetor.
2. Description of the Prior Art
As a method for improving the distribution of the mixture at full load in a multicylinder internal combustion engine, in the past it has been proposed to change the shape of the intake manifold. However, only using this measure has provided no good result. There has been a method in which the riser portion of a intake manifold is heated and a method in which the intake port of a cylinder is choked, but neither of them produces a beneficial result. Further, although a device has been known in which a moving blade, a fixed blade and a pipe with wire mesh are mounted just under a carburetor for enhancing the atomization of the mixture, it is not very effective for the distribution.
The distribution of the mixture to the different cylinders has its quality determined by the directionality of the stream of the mixture supplied from the carburetor. The directionality of the mixture, in turn, varies in dependence on the number of revolutions of the engine. In particular, in case of a multiple barrel carburetor, the directionality varies at every actuation of each barrel. For this reason, even though the distribution is effective at a certain number of revolutions of the engine, conversely it becomes ineffective when the engine revolves at a different speed.